Kate, showing off her super-slim figure in a white dress, looked on at new displays featuring her iconic wedding dress (designed by Sarah Burton of Alexander McQueen), tiara, earrings, jewelry -- and even her wedding cake!

And the Queen, 85, showed where her grandson Willam, 29, got his wicked sense of humor. As she and Kate looked at the wedding dress, the Queen quipped of the display, mounted on headless mannequin, "Horrid, isn't it? Horrid and dreadful!"